Adjustable Screen Tensioning System

ABSTRACT

An adjustable screen re don system is presented. The present invention screen retention system comprises a mesh Of perforate screen retained within a frame composed of frame members have channel cross sections. The screen is formed with a rolled or U-shaped edge hem. The edge hem having a free edge that folds inwardly over the inner face of the screen and is parallel to, and spaced above, the inner face of the screen. The framing members are channel section extrusions which contain features for retaining, tensioning and locking the screen. The adjustable screen retention system herein presented improves upon the prior art by providing a more secure attachment of the screen within the channel of the frame members thereby providing increased resistance to screen impact loading. The new system also provides for a broader range of screen of tensioning adjustment than has heretofore been available and further electrically isolates the screen from the walls of the channel.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to screens for windows, doors and thelike, and in particular, to a screen retention assembly for securing ascreen to a frame or surround. The invention presented is primarilyintended for security screens that deter human intruders and provideimpact protection from flying debris. However, the system may also beused for security screens that prevent the intrusion of insects andsmall animals into a building.

2. Background of the Invention

Doors or windows incorporating a semi-transparent screen or mesh providethe advantages of visibility, ventilation, and also the ability toprevent the passage of insects or small animals through the aperturecovered by the screen. Screens are typically made from a flexible wiremesh although other flexible or semi-rigid perforate sheet materials maybe used.

Common prior art screen systems attach the mesh directly to theperimeter of the window or door opening with simple fasteners such asscrews, rivets or glue. While such systems are functional, they lack ameans of applying tension to the screen upon installation. A tensionedscreen is important because ordinary use of a door or window oftencauses repeated impact loads to the screen, for example pushing the dooropen by pushing or kicking the screen. Thus, the semi-rigid material ofthe screen often appears floppy after a short period of ordinary use.

The strength and appearance of a screen attached using simple fastenersis also overly dependent on the skill of the fabricator. For example, ifthe screen is cut slightly too small, the screen will be weakened andsubject to pulling out of the frame because the fasteners will be tooclose to the edge of the mesh. If glue is used, it will not sufficientlycover enough surface area of the mesh to create a strong bond. On theother hand, if the screen is cut slightly to large, then the mesh willbe unavoidably floppy because the use of simple fasteners provide nomeans for tensioning the mesh.

To overcome many of the weaknesses of directly fastening a screen to theperimeter of a window or door opening, more modern systems that framethe openings with extruded metal, typically aluminum, channel sectionshave been developed, wherein the edges of the screen are secured withinthe channel walls. A wide variety of means for securing screens withinthe channel walls have been developed. Prior art systems range fromsimple friction fits between the screens and the channels to complexturnbuckle like fasteners mounted in the channels which grip and tensionthe screen.

Screen retention systems that feature channel section frames about theperimeter of door or window opening have effectively overcome many ofthe drawbacks of systems that attached the screen directly to the dooror window frame. Aesthetic appearance has been improved due to the lackof visible fasteners. Function has also been improved because some ofthe prior channel section screen retention systems have some ability totension the screen.

Prior an channel-based screen retention systems do suffer from certaindrawbacks however. In particular, prior art systems typically use flator screen edges which allow for only a very limited amount of screentensioning and offer only modest resistance to screen impact loading.When screen tensioning provisions are specifically provided, theynevertheless often have a very limited adjustment range. In addition,many prior art screen retention systems allow the metal of the screen,typically iron or steel, to contact the wall of the, typically aluminum,channel. This contact of dissimilar metals allows for galvanic corrosionat the interface between the screen and the channel. Power coatedstainless steel is the preferred material for security screens. Commoninsect screens are typically made using vinyl coated fiber glass,aluminum mesh, galvanized steel, bronze, stainless steel, or vinylcoated polyester.

What is needed in the art is an improved channel-based screen retentionsystem that provides a more secure attachment of the screen within thechannel to provide increased resistance to screen impact loading. Alsodesirable is a broader range of screen of tensioning adjustment and fora design that electrically isolates the screen from the walls of thechannel, when the channel and screen are both made from metallicmaterials as is commonly the case.

SUMMARY OF THE INVENTION

It is the purpose of the present invention to provide an improvedchannel-based screen retention system that increases the resistance toscreen impact loading; provides for a broad range of screen tensioningadjustability, and that electrically isolates the screen from the wallsof the channel to prevent galvanic corrosion, among other features.

The invention comprises a screen retention system comprised of a screenretained within a frame, the frame being composed of frame membershaving channel cross sections. In the exemplary embodiment, the framemembers are extrusions, the outer perimeter of which frame a window,door, or like structure, or are designed to be received within theopening of a door, window, or like structure, where it is desired toclose out the opening with a screen. The mesh or perforate screenfeatures an inner face and an outer face. The perimeter of the screen isformed with a rolled or u-shaped edge hem. The edge hem having a flangewhich folds inwardly over the inner face of the screen and is parallelto, and spaced above, the inner face of the screen.

The inner perimeter of the members which form the frame for the screeninclude an opening or main channel for receipt of the screen. In crosssection, an upper interior wall of the main channel of each frame memberhas a serrated surface while an opposing lower, interior wall features apair of spaced apart inner and outer interior longitudinal channels. Theinterior longitudinal channels serve to secure an elastomeric gasket. Asubstantial depth of clear space exists inwardly of the serrations and abottom of the main channel. The depth of free space allows for a broadrange of adjustability for tensioning the screen.

The elastomeric gasket features a pair of spaced apart, longitudinallyrunning per and lower ribs featuring a bulb style cross section forengagement with the mating spaced apart inner and outer interiorlongitudinal channels formed in the lower interior wall of the mainchannel of the frame members. On an opposite side, the elastomericgasket has serrations for engaging the mesh or perforations of thescreen. The screen is inserted into the channel sections such that theu-shaped hem of the screen faces away from the serrations in theelastomeric gasket.

The screen is locked into place within the channel of the frame membersby means of a plurality of locking tabs. In the exemplary embodiment,the locking tabs are of generally rectangular cross-section and arecomposed of a deformable material. One face of the tabs includesserrations. During assembly, the locking tabs are inserted into thechannel of the frame members between the inner face of screen and theupper interior wall of the channel. The screen is locked into place andtensioned by pressing the locking tabs downwardly into the channel suchthat the serrated face of the tabs engages the serrations on the upperinterior wall of the channel while a perpendicular face of the tabsengages an upper edge of the flange of the u-shaped hem on the screen.The degree of screen tension is controlled by the insertion depth of thetabs. During tab insertion the fixed elastomeric gasket beneath thescreen mesh is compressed and provides a constant force to hold the tabsin position.

After the screen has been secured within the channel of the framemembers as described above, an elastomeric gasket is partially insertedinto the opening between the inward face of the screen and the upperinterior wall of the channel for the purpose of sealing out theelements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a perspective view of a framed screenfor closing out an aperture;

FIG. 2 is a partial side sectional view through the line A-A of FIG. 1,showing the components of an adjustable screen retention assembly inaccordance with an illustrative embodiment of the present invention,showing the main channel, screen, retention gasket, locking tab(s) andsealing gasket, among other features.

FIG. 3 is a partial side sectional view through the line A-A of FIG. 1,showing the components of an adjustable screen mention assembly inaccordance with the illustrative embodiment of FIG. 2, with the sealinggasket removed.

FIG. 4 is a partial side sectional view through the line A-A of FIG. 1,of the components of an adjustable screen retention assembly inaccordance with the illustrative embodiment of FIG. 2, with the outersealing gasket, screen and locking tabs removed.

FIG. 5 is a partial side sectional view of the screen used in theillustrative embodiment of the adjustable screen retention assembly ofFIG. 2.

FIG. 6 is a cross sectional view of the locking to shown in theillustrative embodiment of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. The invention may, however, may be embodiedin many different forms and should not be construed as being limited tothe embodiments set forth herein. Rather these embodiments are providedso that this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout.

With reference to FIG. 1, there is illustrated a screen retention system10 having a frame 12 comprised of elongate frame members 14 havingchannel cross sections 18 with a mesh or perforate screen 16, attachedto the frame members 14. The screen 16 covers the opening enclosed bythe frame 12. In the exemplary embodiment of FIG. 1, the screenretention system 10 is shown as having a discrete frame 12, the outsideperimeter of which is sized to fit within an opening in a door, wall orother structure having an aperture. It should be understood however,that the present invention is net limited to a discrete frame or anyparticular style or shape of frame. In alternative embodiments, theframe 12 may form the primary structural frame for a door, window insetin a wall, or other structure where an aperture is desired.

With reference to FIGS. 2-4, the cross-section 18 of the channel of theframe members 14 of the screen retention system 10 of the presentinvention is depicted along with the screen 16, screen retention orretaining gasket 20 at least one locking tabs 22 and sealing gasket 24which comprise the major components of the screen tensioning system 10.

Referring now to FIG. 5, the mesh or perforate screen 16 features aninner face 26 and an outer face 28. The perimeter of the semen 16 isformed with a rolled or u-shaped edge horn 30. The edge hem 30 has aflange 32 which folds inwardly over the inner face 26 of the screen 16and is parallel to, and spaced above, the inner face 26 of the screen16. The screen 16 may be made from a wide variety of mesh or perforatematerials. Wire mesh made from virtually all plastically deformablemetallic materials including steel, iron, and aluminum, among others, issuitable. Wire mesh made from type 304 stainless steel is oneparticularly preferred screen material. Perforate plastic sheetmaterials that can be formed with the edge hem 30 or its functionalequivalent, are also suitable. A stepped surface around the border of aplastic sheet material would be the functional equivalent of the edgehem 30 in a wire mesh material

Referring now to FIGS. 2-4, the channel 18 of the frame members 14features an upper interior wall 36 and a lower interior wall 38. Theupper interior wall 36 includes a serrations 40 for engaging the atleast one locking tabs 12. The opposing lower interior wall 38 featuresa pair of spaced apart inner 44 and outer 42 lower interior longitudinalchannels. The lower interior longitudinal channels 42 and 44 serve toreceive and retain the semen retention gasket 20. The inner 44 and outer42 lower interior longitudinal channels both feature inwardly facingretaining flanges 48 (see FIG. 4), which serve to capture and retaininner longitudinal ribs 50 and 52 of the screen retaining gasket 20. Theinner and outer longitudinal ribs 50 and 52 have a bulb-style crosssection 51 which is retained by the inwardly facing retaining flanges48. A substantial depth of free space 46 (see FIG. 4) exists inwardly ofthe lowermost of the serrations 40 and a bottom surface 54 of thechannel 18. The depth of the free space 46 allows for a broad range ofadjustability with respect to tensioning the screen 16. The framingmembers 14 may be made from a variety of metallic and plastic materials.One exemplary preferred material is extruded aluminum.

Referring to FIG. 4, the screen retention gasket 20 features the spacedapart, longitudinally miming upper 50 and lower 52 ribs with abulb-style cross section 51 on an inner face 56 of the gasket 20 forengagement with the spaced apart inner 42 and outer 44 lower interiorlongitudinal channels formed in the lower interior wall 38 of thecross-section 18 of the framing members 14. On an opposite outer face 58of the gasket 20 are serrations 60 for engaging the mesh of the screen16. The screen 16 is inserted into the channel section 18 such that theu-shaped hem 30 of the screen faces away from the serrations 60 in theretaining gasket 20. The screen retention gasket 20 may be made from avariety of elastomeric materials as well as deformable plasticmaterials.

The screen 16 is locked into place within the channel section 18 of eachframe member 14 by means of the at least one locking tabs 22. Referringnow to FIG. 6, in the exemplary embodiment, the at least one lockingtabs 22 are of generally rectangular cross-section having a serratedupper face 62 and a planar lower face 63, as well as planar edge faces64. In the exemplary embodiment, the at least one locking tabs 22 andare composed of a deformable material.

Referring now to FIGS. 2-4, during assembly, the at least one lockingtabs 22 are inserted into the channel 18 between the inner face 26 ofthe screen 16 and the upper interior wall 36 of the channel 18. Thescreen 16 is locked into place and tensioned by pressing the at leastone locking tabs 22 downwardly into the channel 18 such that theserrated upper face 62 of the at least one locking tabs 22 engages theserrations 40 on the upper interior wall 36 of the channel 18 while oneof the perpendicular edge faces 64 of the at least one locking tabsengages the upper edge 34 of the flange 32 of the u-shaped hem 30 of thescreen 1. The planer lower face 63 of the at least one locking tabs 22abuts the interior face 26 of the screen 16. The degree of screentension is controlled by the insertion depth of the at least one lockingtabs. The free space 46 of the channel 18, provides clearance for thehem 30 of the screen 16 to be pressed downwardly within the free space46 and therein allows for screen tension adjustability.

In the exemplary embodiment, the serrations 40 of the upper interiorwall 36 of the channel 18 are made from a material comparatively harderthan that of the at least one locking tabs 22 to ensure that theserrations 40 of the channel 18 engage and plastically deform the matingserrations 62 the locking tabs 22. The material of the retention gasket20 is comparatively softer than that of the screen 16, such that theserrations 60 of the gasket 20 engage with the mesh or perforations 15in the screen 16.

After the screen 16 has been secured within the channels 18 of the framemembers 14 as described above, an elastomeric sealing gasket 24 ispartially inserted into the opening between the inward face of thescreen 16 and the upper interior wall 36 of the channel 14 for thepurpose of sealing out the elements.

The above described screen retention system 10 presents severaladvantages over the prior art. In particular, the free edge 34 of thescreen 16 does not require the addition of an electrical insulatorbecause the at least one locking tabs 22 are themselves made (in theexemplary embodiment) from an insulating material, but more importantlythe free edge 34 of the screen 16 does not face toward the dissimilarmetal (in the exemplary embodiment aluminum) of the upper and lowerinterior walls 36 and 38 of the channel 18 of the frame members 14, butinstead faces toward one of the planer edge faces 64 of the at least onelocking tabs 22, thereby preventing dielectric corrosion.

In addition more force can be applied to edge hem 30 of the screen 16 ofthe present invention without distortion of free edge 34 duringtensioning of the screen 16, as compared to, for example, aperpendicular lip as may be found in some prior art designs. This isimportant because a more highly tensioned screen 16 improves theaesthetics of the finished product, and for security screen applicationscan withstand greater impact due m it's improved pullout strength. Thescreen 16 of the present invention 10 may also be more centrally locatedwithin the frame 12 preventing an imbalance of the sealing gasket 24 andretention 20 gasket thicknesses, which further contributes to improvedappearance. The screen's 16 tension is maintained by compressive forcefrom the retention gasket 20, holding serrated surface 62 of the atleast one locking tab 22 into the matching serrations 40 of the upperinterior wall 36 of the frame members 14. The screen retention gasket 20has a high degree of compressibility which allows for the use of screensof different thickness (wire thicknesses in the case of wire meshscreens) without the need to use gaskets of differing thicknesses.

Also, the edge hem 30 of the screen 16 of the present invention hasmanufacturing advantages over the L-shaped edge hem used in some prioran designs in that formed screens can be stacked after the formation ofedge hem 30 without risk of damage to the protective finish of adjacentscreens 16, as the free edges 34 of the screen are parallel to the planeof the screen. Screens featuring the U-shaped edge hem 3 of the presentinvention can be more easily guided into frame members having a narrowopening without risk of damage to the semen doe to the rounded edgeprofile as compared to the abrupt square or sharp edge of an L-shapededge hem design. Further manufacturing efficiency is realized due to thefast installation of the tabs as compared to tensioning with a multitudeof fasteners.

The foregoing detailed description and appended drawings are intended asa description of the presently preferred embodiment of the invention andare not intended to represent the only forms in which the presentinvention may be constructed and/or utilized. Those skilled in the artwill understand that modifications and alternative embodiments of thepresent invention which do not depart from the spirit and scope of theforegoing specification and drawings, and of the claims appended beloware possible and practical. It is intended that the claims cover allsuch modifications and alternative embodiments.

1. A screen retention assembly, comprising: a frame assembly composed ofa plurality of frame members configured to frame an aperture, each framemember having a main channel; a screen, the screen closing out theaperture; wherein the semen includes an inner face and an outer face anda free edge, the free edge being folded inwardly along a perimeter ofthe screen to form an hem edge, a folded portion of the free edgeextending inwardly from the hem edge, over the inner face of the screen;wherein the main channel of the frame members includes an upper interiorwall, a lower interior wall, the upper interior wall including aserrated surface, the lower interior wall including spaced apart, innerand outer longitudinal channels; a retention gasket, wherein theretention gasket includes an inner face and an outer face, the innerface featuring two spaced apart longitudinal ribs, the outer faceincluding a serrated surface; at least one locking tab, wherein the atleast one locking tab has a serrated face and an opposite and parallel,planer face, and at least one perpendicular edge face; wherein the innerand outer longitudinal ribs of the retention gasket are retained withinthe inner and outer longitudinal channels of the lower interior wall ofthe main channel; wherein, the screen is disposed between the lower andupper interior walls of the main channel and abuts and engages theserrated surface of the outer face of the retention gasket; and wherein,at least one of the at least one locking tabs is disposed between theinner face of the screen and the upper interior wall of the mainchannel, of each frame member, wherein the serrated face of the at leastone locking tab engages the serrated surface of the upper interior wallof the channel and a planar edge at least one locking tab perpendicularto the serrated face abuts the free edge of the screen.
 2. The screenretention assembly of claim 1, wherein the inner and outer interiorlongitudinal channels each have a pair of opposed longitudinal retainingflanges and the inner and outer longitudinal ribs of the retentiongasket are bulb-shaped in cross-section for engagement with theretaining flanges of inner and outer interior longitudinal channels. 3.The screen retention assembly of claim 1, wherein main channel of theframe members has a bottom wall separated by a free space defined as thedistance from the bottom wall to a lower edge the serrated surface ofthe upper interior wall of the channel.
 4. The screen retention assemblyof claim 1, further including a gasket disposed between the inner faceof the screen and the upper interior wall of the main channel, wherebythe gasket servers to seal out the elements.
 5. The screen retentionassembly of claim 1, wherein the main channel and the screen are madefrom electrically conductive materials and the at least one locking tabsand retention gasket are made from electrically nonconductive materials.6. The screen retention assembly of claim 1, wherein the at least onelocking tabs are composed of a plastically deformable material which issofter than that of the main channel.
 7. A screen retention assembly,comprising: a frame assembly composed of a plurality of frame membershaving a main channel, configured to frame an aperture; a screen, thescreen closing out the aperture; wherein the screen includes an innerface and an outer face and a free edge, the free edge being foldedinwardly along a perimeter of the screen to form a hem edge, a foldedportion of the free edge extending inwardly from the hem edge, over theinner face of the screen; wherein the channel of the frame membersincludes an upper interior wall and a lower interior wall, the upperinterior wall including a serrated surface; and means for securing thescreen within the main channel of the frame members.
 8. The screenretention assembly of claim 7, wherein the means for securing the screenwithin the main channel comprises: a retention gasket, wherein theretention gasket includes an inner face and an outer face, the outerface including a serrated surface; a plurality of locking tabs, whereineach locking tab has a serrated face and an opposite and parallel,planer face, and at least one perpendicular edge face; means forsecuring the inner face of the retention gasket to the lower interiorwall of the main channel; the screen being disposed between the lowerand upper interior walls of the main channel and abutting and engagingthe serrated surface of the outer face of the retention gasket; andwherein the at least one locking tabs is disposed between the inner faceof the screen and the upper interior wall of the channel, for each framemember, wherein the serrated face of the at least one locking tabsengages the serrated surface of the upper interior will of the channeland the opposite parallel planer face abuts the inner face of the screenand the at least one perpendicular edge face abuts the free edge of thescreen.
 9. The screen retention assembly of claim 8, wherein means forsecuring the inner face of the retention gasket to the lower interiorwall of the main channel comprises: inner and outer interiorlongitudinal channels formed on the lower interior wall of the mainchannel which engage longitudinal ribs formed on the inner face of theretention gasket.
 10. The screen retention assembly of claim 9, whereinthe mewls for securing the inner and outer interior longitudinalchannels formed on the lower interior wall of the main channel furtherincludes: a pair of mutually opposed longitudinal retaining flanges oneach of the inner and outer lower interior longitudinal channels; andwherein the longitudinal ribs formed on the inner face of the retentiongasket are bulb-shaped in cross-section, wherein the bulb-shaped crosssection of the longitudinal ribs is retained by the retaining flanges ofthe inner and outer interior longitudinal channels.
 11. The screenretention assembly of claim 7, wherein main channel of the frame membershas a bottom wall separated by a free space defined as the distance fromthe bottom wall to a bottom edge of the serrated surface of the upperinterior wall of the channel.
 12. The screen retention assembly of claim7, further including a gasket disposed between the inner face of thescreen and the upper interior wall of the main channel, whereby thegasket servers to seal out the elements.
 13. The semen retentionassembly of claim 7, wherein the main channel and the screen are madefrom electrically conductive materials and the at least one locking tabsand retention gasket are made from electrically nonconductive materials.14. The screen retention assembly of claim 8, wherein the at least onelocking tabs are composed of a plastically deformable material which issofter than that of the main channel.
 15. A screen retention assembly,comprising: a frame assembly composed of a plurality of frame membersconfigured to frame an aperture, each frame member having a mainchannel; a screen, having a free edge, the screen closing out theaperture; a retention gasket, disposed between a lower interior wall ofthe main channel and the screen; at least one locking tab, disposedbetween an upper interior wall of the main channel and the screen;wherein, the upper interior wall of the main channel includes a serratedsurface which engages with a mating serrated face on the at least onelocking tab; wherein the retention gasket has a serrated surface whichengages with the screen; and wherein the at least one locking tab has aface that abuts the tree edge of the screen.
 16. The screen retentionassembly of claim 15, wherein the screen includes an inner face and anouter face and the free edge, the free edge being folded inwardly alonga perimeter of the screen to form a hem edge, a folded portion of thefree edge extending inwardly from the hem edge, over the inner face ofthe screen.
 17. The screen retention assembly of claim 15, wherein thelower interior wall of main channel of the frame members includes spacedapart, inner and outer lower longitudinal channels.
 18. The screenretention assembly of claim 16, wherein the retention gasket includes aninner face, the inner face featuring two spaced apart longitudinal ribs,which engage the spaced apart inner and outer lower longitudinalchannels of the lower interior wall of the channel of the frame members.19. The screen retention assembly of claim 15, further including agasket disposed between the inner face of the screen upper interior wallof the main channel, whereby the gasket serves to seal out the elements.20. The screen retention assembly of claim 15, wherein the main channeland the screen are made from electrically conductive materials and theat least one locking tabs and retention gasket are made fromelectrically nonconductive materials.